Mr Iloh and Mr Leboea were arrested at the Urbana Langsuan Hotel and Mr Agu at a 7-Eleven store in the same area.

Pol Maj Gen Rewat said the bureau worked on a tip-off from informants that the three were sending the drug to African customers in Bangkok and put them under surveillance before the arrest.

They were charged with drug possession and intent to sell.

Their arrest underlined concern of anti-drug police about widespread drug activities involving Africans staying in the country, he said.

African nationals are being targeted by the bureau after reports that 15,000 visitors from the continent are living illegally living in Thailand.

Meanwhile, seven suspects have been arrested in separate raids in Bangkok and Samut Sakhon and 620,000 methamphetamine tablets and 12kg of crystal meth, known as ya ice, seized.

The suspects – three Chinese Haw men, three Nigerian nationals and one Thai Muslim – were paraded at a press briefing at the Narcotics Suppression Bureau (NSB) in Bangkok on Thursday.

A total of 620,000 speed pills, 12 kg of crystal methamphetamine, a Toyota Fortuner, a motorcycle and other items were seized from the suspects, said NSB acting chief Rawat Klinkasorn.

In the first raid, the Chinese Haw men identified later as Siang-er sae Seng, Siew-ieo sae Tuan and Surat sae Yang, were caught separately at Soi Phetchakasem 95 and a commercial building in Samut Sakhon’s Krathum Baen district.